Field
Embodiments of the present disclosure generally relate to a method of and a system and apparatus for texturizing a surface of a component for use in a semiconductor processing chamber.
Description of the Related Art
As integrated circuit devices continue to be fabricated with reduced dimensions, the manufacture of these devices becomes more susceptible to reduced yields due to contamination. Consequently, fabricating integrated circuit devices, particularly those having smaller physical sizes, requires that contamination be controlled to a greater extent than previously considered to be necessary.
Contamination of integrated circuit devices may arise from sources such as undesirable stray particles impinging on a substrate during thin film deposition, etching, or other semiconductor fabrication processes. In general, the manufacturing of the integrated circuit devices includes the use of chambers, including, but not limited to, physical vapor deposition (PVD) sputtering chambers, chemical vapor deposition (CVD) chambers, and plasma etching chambers. During the course of deposition and etch processes, materials often condense from the gas phase onto various internal surfaces of the chamber and surfaces of chamber components disposed within the chamber. When the materials condense from the gas phase, the materials form solid masses that reside on the chamber and component surfaces. This condensed foreign matter accumulates on the surfaces and is prone to detaching or flaking off from the surfaces during or in between a wafer process sequence. This detached foreign matter may impinge upon and contaminate the wafer and devices formed thereon. Contaminated devices frequently must be discarded, thereby decreasing the manufacturing yield of the process.
In order to prevent detachment of foreign matter that has formed, the internal surfaces of the chamber and the surfaces of chamber components disposed within the chamber may be provided with a particular surface texture. The surface texture is configured such that the foreign matter that forms on these surfaces has enhanced adhesion to the surface and is less likely to detach and contaminate a wafer. A key parameter of the surface texture is the surface roughness.
One common texturizing process is bead blasting. In a bead blasting process, solid blasting beads are propelled towards the surface to be texturized. One manner in which the solid blasting beads can be propelled towards the surface to be texturized is by pressurized gas. The solid blasting beads are made of a suitable material, for example, aluminum oxide, glass, silica, or hard plastics. Depending upon the desired surface roughness, the blasting beads can be of varying sizes and shapes.
However, it can be difficult to control the uniformity and repeatability of the bead blasting process. Moreover, during the bead blasting process, the surface being texturized may become sharp and jagged such that tips of the surface break off because of the impact of the solid blasting beads, thereby introducing a source of contamination. In addition, the blasting beads may become entrapped or embedded within the surface during the bead blasting process. For example, if the surface being texturized includes a small through-hole of a varying width (e.g., a gas distribution showerhead), the blasting bead may become entrapped within the through-hole. In such a situation, the blasting bead not only prevents the through-hole from functioning as a gas passageway, for example, but it also introduces a potential source of contamination for a wafer.
An electromagnetic beam can also be used to texturize a chamber surface. Using an electromagnetic beam to texturize a chamber surface may overcome some of the above-identified problems associated with bead blasting. However, the electromagnetic beam must be operated under vacuum to prevent scattering. Scattering can occur when electrons within the electromagnetic beam interact with air or other gas molecules. Consequently, the electromagnetic beam must be operated within a vacuum chamber. The need for a vacuum chamber limits the size of components that can be texturized because the component must be able to fit within the vacuum chamber. Moreover, the capital costs associated with operating an electromagnetic beam are significantly higher than the capital costs associated with bead blasting process. For example, the need for a vacuum chamber increases the costs associated with texturing a surface with an electromagnetic beam.
Therefore, there is a need for an improved texturizing process that overcomes the problems associated with bead blasting while avoiding the capital costs and size constraints associated with the use of an electromagnetic beam.